Machine for grinding tubes



Feb. 14, 1939. H. H. MINER 2,147,453

MACHINE FOR GRINDING TUBESL Filed Aug. 6, 1936 HNVENTOR HARRY l MINER BY ATTORNEY Patented Feb. 14, 1939 PATENT OFFICE MACHINE FOR GRINDING TUBES Harry H. Miner, Paris, France, assignor .to Landis Tool Company, Waynesboro, Pa., a corporation Application August 6, 1936, Serial No. 94,705

6 Claims.

My invention relates to grinding machines especially those for grinding the external surfaces of tubular work pieces.

It is an object of the invention to provide means to cool the work internally during a grinding operation and thereby prevent warping of same due to heat generated by the grinding operation.

A further object is to provide means for automatically filling the tubular work piece with water or other cooling fluid after it has been placed in the machine,

A further object is to insure maximum contact between cooling medium and the surface of the work.

Previous to my invention, when it was desired to grind tubular work pieces, each piece was filled and sealed before it was put in the machine and emptied after it had been ground and removed from the machine.

My invention contemplates filling the work piece by introducing a cooling medium thru one of the work centers after the work has been placed in the machine. The center acts as a stopper to hold the water in the work piece during the grinding operation. This method eliminates the operations of filling, sealing, andeniptying the work piece since all these functions are performed in the operations of placing the work in and removing it from the machine.

Referring to the drawing:

The figure is a front elevation of a grinding machine with a partial sectional view of the head stock to show the application of my device.

Since we are concerned only with the structure included in the invention, this description will be confined to such structure.

Numeral indicates a tubular work piece, in this case a housing for the rear axle of an automobile. This piece has a number of portions of varying diameters, three of which are ground simultaneously in the machine. Numerals H and I2 indicate the head and tail stock respectively. The tail stock center I3 is of more 'or less conventional construction and acts as a stopper for one end of the work piece. The center and work do not ordinarilyfit closely enough to prevent the escape of air as the tube is filled. In such a case a small groove out either in the center or in the work would permit the air to escape.

The headstock center I4 also is of conventional construction except that it has been drilled to provide a passage for bringing water to fill the work piece. The headstock center also acts as a stopper to hold water in the work during the grinding operation. Said center is mounted in a hollow headstock spindle I5, driven thru suitable connections by a motor I6. A work driver 32 of any suitable construction is attached to the face plate not shown. A tube IT is threaded into the center l4 and extends beyond the end of the spindle into a fluid connection l8 of any suitable construction. Said connection is secured to the headstock in line with spindle IS. The coolant system of the machine consists, of a supply line 10 34 discharging into at manifold 35 from which coolant is distributed to nozzles 36, 31 and 38. Said nozzles direct the coolant on the portions of the work being ground. Another conduit I9 is connected to said manifold. Said conduit I9 conducts coolant to said fluid connection It. Tube H rotates in said connection and fluid enters said tube thru a series of radial holes therein in alignment with line l9 where it enters connection 18. j A valve in line 19 is connected thru links 20 2| 31161221170 solenoid 23. Valve 20 is operated in one direction by a spring 3| and in the other direction by solenoid 23. These parts as well as the wiring are shown diagrammatically. Said solenoid is connected thru lines 24 and 25 to the 25 lines Hand 2'! which supply current to motor 16 from lines 29 and 30 thru starter 28. If it is desired, the valve 20 and the operating mecha- .nism'for same may be dispensed with and the water permitted to run continually. 30

In the operation of the machine, the work is mounted on the centers in the usual manner. When the head stock motor I6 is started the driver 32 grips and rotates the work I 0. The solenoid 23 is also energized from the motor cir- 35 cult and acts thru links 2| and 22 to open valve 20 thus permitting water to flow thru line l9, tube l1, and center M to fill the work piece Hl. After the grinding operation has been completed the operator stops motor I 6 and at the same time solenoid 23 is deenergized and valve 20 is closed by spring 31, thus stopping the flow of water in line H). As soon-as the work piece is removed from the centers the Water runs out. This of course is much simpler than removing a pipe plug or a screw cap to release the water. If the valve mechanism is not used, the water runs continually and the work is filled as soon as it is mounted on the centers. Work supporting means other than centers may be used within the scope of my invention if provision is made to supply a suflicient volume of cooling fluid to the inside of the work.

Various changes may be made in my device without departing from the spirit of the invention, therefore, I do not wish to limit myself to the structure shown and described in the drawing and specification but only as indicated in the following claims.

1. In a machine of the kind described a work support, means for supporting a tubular work piece thereon, means for rotating said work piece comprising a motor, a switch for starting said motor, means for filling said work piece with a cooling medium comprising a supply of same, connections between said supply and said work piece including a valve, a solenoid for operating said valve and means for energizing said solenoid when said motor is started.

2. In a machine of the kind described, a wheel support, a grinding wheel mounted thereon, a work support, means for feeding one of said sup- Ports toward the other to perform a grinding operation, a head stock and a tail stock on said work support, work centers in each of said parts for supporting and centering a tubular work piece, an axial passage through one of said centers one end of which extends into the work piece beyond the point of contact with said work piece, and means for introducing a cooling medium through said passage to fill the work piece.

3. A machine of the kind described comprising a work support, means on said work support including a pair of centers for centering and supporting a tubular work piece thereon, means for rotating said work piece about said centers, means for filling said work piece with a cooling medium comprising a supply of said cooling medium, a passage for fluid through one of said centers, connections between said supply and said passage, and means operable with said work rotating means for starting and stopping the flow of coolant to said work piece.

4. In a machine of the kind described, a wheel support, a grinding wheel thereon, a work support, means for feeding one of said supports toward the other to perform a grinding operation. a head stock'and a tail stock mounted on said work support, centers in each of said parts for supporting and centering a tubular work piece, one of said centers having an axial passage therethru for introducing a supply of cooling medium into one end of said tubular work piece, the other center serving to seal the opposite end of said work piece against escape of said cooling medium.

5. In a machine of the kind described, a work support, a head stock and a foot stock on said work support, means for supporting a tubular work piece thereon, comprising a pair of work centers, one of which is hollow; means for rotating said work piece, and means for automatically filling said work piece with the cooling medium after said work piece has been placed on said centers.

6. In a machine for grinding the external surface of tubular work, a grinding wheel support movable toward and from a work piece, a grinding wheel rotatably mounted thereon, a work carriage, work supporting means comprising a headstock and footstock on said carriage, work centers in each of said supporting means, a passage for fluid through one of said centers, means for directing a stream of coolant at substantially the point of contact between wheel and work, and means to direct additional coolant through the fluid passage whereby to cool both the inside and outside surfaces of the piece being ground.

HARRY H. IVHNER. 

